Fiber optic cables are widely used for data transmission. These cables are suspended from support structures such as existing high tension electrical towers. Often these fiber optic cables need to be spliced during initial installation to connect different cable runs, and once in operation, for adding additional cable runs, rerouting, maintenance or repair. It is important that this splicing does not interrupt the total data transmission of the cables involved. Because each of these fiber optic cables typically carry hundreds of thousands of different transmission lines via individual fibers, a complete disruption of the cable continuity is not acceptable when access to, for instance, a single fiber is desired. Thus, access must be provided to the individual transmission lines or fibers to implement a new splice at a portion of a fiber optic cable without totally disrupting the continuity of all the associated bundled fibers.
U.S. Pat. Nos. 5,007,701 ('701 patent) and 5,479,554 ('554 patent) both disclose a splice closure apparatus in which a rigid, cylindrical and weather impervious outer structure is open at both ends. A pair of end caps each include an elastomeric sealing material sandwiched between a pair of rigid plates. At least one of the end caps has openings for the passage of cables into the interior of the closure where an anchoring member is positioned to receive the cable ends and secure a splice. The elastomeric sealing material in each end cap is compressed against the sides of the outer cylinder by the plates on either side when a number of through bolts are tightened, thus forming a weather tight seal between each end cap and the cylinder wall. In addition, in each end cap with cable openings, the elastomeric material is simultaneously urged tightly against the cables, thus also forming a weather tight seal between the end cap and the cables. While use of the elastomeric sealing material is suitable under typical weather conditions, it often is not suitable under extreme weather conditions. After exposure to extreme cold or hot temperature, the elastomeric material loses its ability to contract and expand properly. Other disadvantages to existing splice enclosures include a lack of ease of splicing together adjoining cables or cable connections.
There is a need for a splice enclosure that includes plentiful fiber unit storage, large fiber space capacity and can accommodate various types and sizes of cables. Further, a splice enclosure is needed that is easy to use and that minimizes disturbance to previously spliced cables contained within the device when additional spliced cable are added or existing spliced cables are serviced.